Asphalt-surfaced roofing



y 2, 1929- A. R. LUKENS ET AL 1.719.118

ASPHALT SURFACED ROOFING Filed Dec. 29, 1922 Patented July 2, 1929.

. UNITED STA Es; PAVTENTKO'FFICEQ ALAN n. LUKENS, or WYOMING, Ann JOSEPH s. mnimnnn, on CINCINNATI; some,

ASSIGNORS, BY MESNE ASSIGNMENEPS, TO THE FLI NTKOTE COMBANY, vOIE 'IBQS'IOIT, MASSACHUSETTS, A CQRPORATION OF MASSAGHUSETTS.

ASPHALT-SURFACED ROOFING. 7

Application filed December 29, 1922. Serial No. 609,749.

Our invention relates to the surfacing of roofs, and more particularly to the adquate and inexpensive protection of so-called builtup roofs having a layer of asphalt uppermost.

In the construction of built up roofs layers of fibrousmaterial, such as felt composi tion, are placed on the roof structure, and then molten asphaltor tar' is poured onto the felt,

and further layers of felt and asphalt or tar 10 are applied, with the roof being finished with a layer of the molten bitumen, which is covered with crushed slag or clean screened graveL. In the case of asphalt it has not al- Ways been customary to employ any mineral dressing. A tar of suflicient hardness not'to slip ,is very shiny, and will check, crumble and crack unless thickly covered with a dress-.

ing, of gravel or slag, usually weighing 400' themselves with the observation that asphaltsurfaced roofs have proved satisfactory, theory to the contrary notwithstanding.

, In the preparation of prepared roofing it has been the practiceto surface it with crushed slate, which is rolled into the surface, and in the so-called rubber roofing .it

has been the practice to apply a lubricant in the form of talc or mica to prevent sticking.

also, as above noted, it has beenthe practice to provide a hard surface of pebbles or slag for built-up roofs.

, It may be observed that in each of the cases noted there has in fact been applied a coating or dressing of-material which to varying ex- 5 tent, cuts off light from access to the asphalt itself. l i

' In view of tection to the asphalt from actinic' dis integration has been unconscious, the various methods for covering theasphalt. in built-up and prepared roofings have been either ineffective or expensive from the point of view of appli cation.

It is the object of our invention to provide,

the fact, however, that this proand is not known geologicalliash d w as. a no comnasa result of our discoveries, a top dressing for asphalt or other "bituminous roofings of opaque finely divided mineral matter having great surface areaa s "compared to weight, and Y thus to protect-agamst actinlc rayswith the maximum efficiency and at the least ex-= pense.

It is not our object primarily to apply these protective coatings in'the factory onto prepared roofing, since the best form of protective material will-beblack, insoluble, dull in surface, and 'very' permanent in. the weather. I

Such a material, sofar as we have been I able to select one, is always ofa hard abrasive quality, andthu's would be too dangerous to workmen, who would breathe it in, to permit of its use in aclosed factory building. lVith'suitable. protection to the workman it could be used, however,'and would give a very effective, and well appearing rubber roofing product. u 21 The use of slag or pebbles does not fully protect asphalt or tar poured in a layeron the top of a roof structure,1 unless it is quite thick, and 'eventhenv light can get through the cracks between the pebbles. Slag is per- .haps better thanpebbles in this respect. But

in either case the material isquite heavy, and

has a high costof transportation, and is ex-;'-

pensive to use on the building, duet-o transportation and applicationgdifliculties.

Talc or mica used on an asphalt roof, while effective to a partial-degree in protecting against actinic rays, would-not serve as sufiicientsprotection', in our-opinion, were it not for the fact that soot and dust of more opaque 1 quality arealso deposited Jon 'the roof. Both talc and mica are of translucent quality.

' We prefer to use a light powder composed of a dull black colored substance. The dullness makes the substancexlight absorbing, so that it does not reflect light. The act of reflection often serves to permit a considerable uantity of light topenetrate through a thin m of the substance, which is not desired. The substance must also'be insoluble, and

veryperman'ent against corrosion or disintegration, due'to the effects ofthe weather.

, We have found a substance innature composed of ahydrat'ed ferrous-oxide combined with silicomiwhich is amgir I until our 1nvention, herein described,'itj

phous in, quality mercial use. It was called 'by the copper manufacturer which makes the material a by-o product of copper production, a slag powder,

and among many other powdered materials tried, it was the only one which in, a very thin layer would not transmit actinic rays of ii ht.

Referring to the drawings, Figure 1 represents a perspective view of a cut-away corner of a roof in the treatment of which our invention has been used. a Figure 2 represents a cross section ofthe roof portion shown in Figure 1. The powdered mineral matter 1 is shown as spread over the hot'bitumen 2 which is a )plicd on and covers in a thin layer the roo gfelt 3.

A few pounds of this substance scattered or (and) brushed onto a top layer of bitumen in a roof, when same is still hot, will serve to cover a normal layer of several 'himdred pounds of asphalt, and thus a top dressing or coating for builtsup roofs may be provided, using a suitable asphalt, with which can be readily shipped small cans of the product that the workman can carry on his person. The powdery nature of the product insures a complete coverage without chance for seepage of light, this being more or less impractical with larger particles. The powder is applied while the roof is hot, so that it is held fast by the tacky bituminous coating.

The comparison in weight, cost of transportation and expense between the standard gravel or slag finishes for bituminous roofs are naturally very favorable to our top dresslather substances of like characteristics may be obtained and we have-given the above aspreferred because of its cost and physical properties, aside from its light protecting function.

Carboniferous material of lubricating qualit we do not favor, because of the likelihood its running, and thus creating a danger of staining. the sides of a building.

Our experiments have indicated that a roof covered with a layer of plain asphalt with a dark colored non-reflective powder will completely withstand disintegration under tlleinfluence of light, and thus the roofs prepared according to our invention are just as good and much lighter in weight than gravel or sIa'gcovered rbofs, and have an equal or asphalt and a thin surfacing layer of hydrated ferrous oxide combined with silicon in powdery form, said thin layer being sufiicient to out 01f substantially all actinic light rays from access to the asphalt.

ALAN R. LUKENS. JOSEPH S. MAYNARD. 

